A5008862498- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Mineralogy and Gemology Studies
- Geology and Paleoclimatology Research
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Geological Formations and Processes Exploration
- Planetary Science and Exploration
- Geochemistry and Elemental Analysis
- Geotechnical and Geomechanical Engineering
- Paleontology and Stratigraphy of Fossils
- Anorectal Disease Treatments and Outcomes
- Spine and Intervertebral Disc Pathology
- Vacuum and Plasma Arcs
- Mineral Processing and Grinding
- Geotourism and Geoheritage Conservation
- Astro and Planetary Science
- Diamond and Carbon-based Materials Research
- Laser-induced spectroscopy and plasma
- Mining and Gasification Technologies
- Geomagnetism and Paleomagnetism Studies
- Spinal Fractures and Fixation Techniques
- Advanced materials and composites
Romanian Academy
2019-2023
Institutul Geologic al României
2018-2023
Rice University
2008-2012
California Institute of Technology
2008-2009
University of Bucharest
2003-2005
Arc magmas are important building blocks of the continental crust. Because many arc lavas oxidized, continent formation is thought to be associated with oxidizing conditions. On basis copper's (Cu's) affinity for reduced sulfur phases, we tracked redox state from mantle source emplacement in Primary and mid-ocean ridge basalts have identical Cu contents, indicating that states primitive indistinguishable basalts. During magmatic differentiation, content most decreases markedly because...
Continents, especially their Archean cores, are underlain by thick thermal boundary layers that have been largely isolated from the convecting mantle over billion-year timescales, far exceeding life span of oceanic layers. This longevity is promoted fact continents highly melt-depleted peridotites, which result in a chemically distinct layer intrinsically buoyant and strong (owing to dehydration). chemical counteracts destabilizing effect cold state continents. The compositions cratonic...
Xenoliths of subducted crustal origin hosted by Miocene ultrapotassic igneous rocks in the southern Pamir provide important new information regarding geological processes accompanying tectonism during Indo-Eurasian collision. Four types have been studied: sanidine eclogites (omphacite, garnet, sanidine, quartz, biotite, kyanite), felsic granulites (garnet, and basaltic (omphacite garnet), a glimmerite (biotite, clinopyroxene sanidine). Apatite, rutile carbonate are most abundant minor...
Research Article| October 01, 2003 Building the Pamirs: The view from underside Mihai N. Ducea; Ducea 1Department of Geosciences, University Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Valery Lutkov; Lutkov 2Geological Institute Tajik Academy Science, 734063, Dushanbe, Tajikistan Vladislav T. Minaev; Minaev Bradley Hacker; Hacker 3Department Geological Sciences, California, Santa Barbara, California 93106-9630, Lothar Ratschbacher;...
The Talkeetna arc is one of two intraoceanic arcs where much the section from upper mantle through volcanic carapace well exposed. We reconstruct vertical by determining (re)crystallization pressures at various structural levels. thermobarometry shows that tonalites and quartz diorites intruded ∼5–9 km into a estimated stratigraphy to be 7 thick. shallowest, Tazlina Barnette, gabbros crystallized ∼17–24 km; Klanelneechena Klippe ∼24–26 base ∼35 depth. had volcanic:plutonic ratio ∼1:3–1:4....
Thickening of arc lithosphere influences the extent magmatic differentiation and is thereby important for evolution juvenile arcs into mature continental crust. Here, we use mantle xenoliths from late Mesozoic Sierra Nevada in California (USA) to constrain pressure, temperature, compositional deep beneath a arc. These consist spinel peridotites garnet-bearing peridotites. The former are characterized by coarse-grained protogranular textures having bulk compositions indicative high-degree...
<title>Abstract</title> The interactions between plate tectonic processes and ecosystems are well-documented, but the precise influence of evolution on remains elusive. This study investigates Jurassic–Cretaceous Northeastern Asia, where Yanliao Jehol Biotas flourished amid a prominent transition from crustal shortening to extension. To explore impact these ecosystem, we use innovative whole-rock geochemical composition-elevation models, alongside large dataset Late Triassic–Early Cretaceous...
LA-ICP-MS, and XRD were used to investigate representative samples of gypsum collected from four deposits, all them Badenian age: Cheia (Transilvanian Basin, Cluj county), Ivancauti (Moldavian Platform, Botosani Negresti (Moldavide, Neamt county) Moinesti Bacau deposits selected. The main objective this study consisted a geochemical, crystallo-chemical economical potential detailed characterization these deposits.Accordingly, the LA-ICP-MS permitted determining mass fractions 21 elements...
Low‐angle subduction of oceanic lithosphere may be an important process in modifying continental lithosphere. A classic example is the underthrusting Farallon plate beneath North America during Laramide orogeny. To assess relevance this to evolution and composition lithosphere, mantle stratigraphy Mojave Desert was constrained using ultramafic xenoliths hosted Plio‐Pleistocene cinder cones. Whole‐rock chemistry, clinopyroxene trace element Nd isotope data, combination with geothermometry...
Geodetic data, interpreted in light of seismic imaging, seismicity, xenolith studies, and the late Quaternary geologic history northern Great Basin, suggest that a subcontinental‐scale extensional detachment is localized near Moho. To first order, yielding upper crust at any given latitude this region occurs via an M7 earthquake every 100 years. Here we develop hypothesis since 1996, has undergone cycle strain accumulation release similar to “slow slip events” observed on subduction...
Abstract Rare ultrahigh‐temperature–(near)ultrahigh‐pressure (UHT–near‐UHP) crustal xenoliths erupted at 11 Ma in the Pamir Mountains, southeastern Tajikistan, preserve a compositional and thermal record mantle depths of material subducted beneath largest collisional orogen on Earth. A combination oxygen‐isotope thermometry, major‐element thermobarometry pseudosection analysis reveals that, prior to eruption, partially equilibrated conditions ranging from 815 °C 19 kbar 1100 27 for eclogites...
Retrograde eclogites (ranging from unaltered eclogite to retrograde blueschist and greenschist mantling the boulders) Ring Mountain on Tiburon Peninsula, near San Francisco, California, were examined for whole-rock major trace elements assess protolith compositions geochemical signature of fluids associated with retrogression. High field strength are highly correlated, indicating relatively immobile conservative behavior during These used relative losses or gains other Rare earth FeO content...
The San Emigdio and related Pelona, Orocopia, Rand Sierra de Salinas schists of southern California were underplated beneath the Nevada batholith adjacent along a shallow segment subducting Farallon plate in Late Cretaceous to early Tertiary time. These subduction accretion assemblages represent regional, deeply exhumed, shallowly dipping domain from an ancient slab segmentation system record complete life cycle process initial flattening compression final extensional collapse. An important...
Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) analyses of B and Li in serpentinized peridotites from the Feather River Ophiolite (California) indicates that is enriched serpentine minerals compared to whole‐rock less altered olivine grains, while depleted or comparable Li. The high contents correlate with relatively contents. low are consistent suggest only small amounts were added during serpentinization some was even leached out. A simple model partial melting...
The causes for spatial geochemical trends in the central Andes of Peru have been studied since early 1970s. Along-arc chemical changes observed Peruvian Coastal Batholith (PCB) were fundamental to developing models evolution Pacific margin South America. However, explanations these and processes that control magmatic compositional diversity along this arc are not fully understood. In contribution we use an up-to-date database high quality geochronological data to: 1) assess evidence...
Abstract The Pleistocene (1.65 Ma) Crystal Knob volcanic neck in the California Coast Ranges is an olivine‐plagioclase phyric basalt containing dunite and spinel peridotite xenoliths. erupted through Nacimiento belt of Franciscan complex adjacent to Salinian crystalline nappes. Its xenoliths sample mantle lithosphere beneath outboard exhumed remnants southern Cretaceous subducting margin. This set augments previously studied xenolith suites Mojave Desert Sierra Nevada, which linked...
Abstract A database containing previously published geochronologic, geochemical, and isotopic data on Mesozoic to Quaternary igneous rocks from the Carpathian‐Pannonian region is presented. Georeferenced making up this belong mostly sampled five magmatic arcs: (a) South Apuseni Jurassic island arc/backarc province, (b) a small volume mid‐Cretaceous arc of northernmost Carpathians, (c) late Cretaceous arc, locally known as “banatitic,” marking closure Neotethys, (d) regionally extensive...